Shutoff valve

ABSTRACT

A shutoff valve incorporating a plunger piston which carries at least one axially compressible sealing ring for sealing the piston against the valve housing, and which in each actuated position is subjected to an axial elastic compression which increases in the closed position of the valve plunger piston during further movement of an actuation spindle carrying the piston in the valve closed direction. The sealing ring is clamped between a first piston part or portion and an annular spring which cooperates with a second piston part or portion. In the closed position of the plunger piston, this annular spring bears against a stop fixed to the valve housing, so that the annular spring is displaced relative to both piston parts which are fixedly connected with one another during further movement of the actuation spindle in the closed direction of the valve in the sense of exerting an additional axial compression upon the sealing ring.

United States Patent 191 Huber et al.

[ MSHUTOFF VALVE [75] Inventors: Richard Huber, Modling Bei Wien,

Austria; Peter Wirz, Unterkulin/Aargau, Switzerland [30] ForeignApplication Priority Data 1451 Feb. 26, 1974 1 Primary Examiner-l-IaroldW. Weakley Attorney, Agent, or Firm-Werner W. Kleeman 57 ABSTRACT Ashutoff valve incorporating a plunger piston which carries at least oneaxially compressible sealing ring for sealing the piston against thevalve housing, and which in each actuated position is subjected to anaxial elastic compression which increases in the closed position-of thevalve plunger piston during further movement of an actuation spindlecarrying the piston in the valve closed direction. The sealing ring isclamped between a first piston part or portion and an annular springwhich cooperates with a second piston part or portion. In the closedposition of the plunger piston, this annular spring bears against astopfixed to the valve housing, so that the annular spring is displacedrelative to both piston parts'which are fixedly connected with oneanother during further movement of the actuation spindle in the closeddirection of the valve in they sense of exerting an additional axialcompression upon the sealing ring.

13 Claims, 2 Drawing Figures Mar. 8, 1972 Switzerland .5. 3401/72 52 us.01. .1 251/189, 251/191 [51] Int. Cl. F16k 11/14 [58] Field of Search251/176, 186, 189, 191; 132/630.l4

[56] References Cited 7 UNITED STATES PATENTS v 1,781,224 11/1930 011g251/191 3,211,418 10 1955 Klinger-Hohr.... 25l/l76 3,623,508 11 1971Huber 251 191 FOREIGN PATENTS OR APPLICATIONS 821,565 10/1959 GreatBritain 25 1/191 The present invention broadly relates to the valve artand, more specifically, relates to a new and improved construction ofshutoff or cutoff valve having a plunger piston which carries at leastone axially compressible sealing ring for sealing .against the housingand which in each actuation position is subjected to an axial elasticcompression which increases in the closed position of the valve duringfurther movement of an actuation spindle carrying the plunger pistonwhen such spindle moves in the closed direction.

Valves of this type possess the advantage in contrast to other plungerpiston valves with sealing rings that such, even during longeroperatingperiods in which the valve remains open, do not become loosened(without being squeezed or forced out) owing to the continuous elasticcompression, therefore, possess greater longevity. The additionalcompression in the closed state of the valve provides the requiredradial bearing contact at the valve seat.

SUMMARY THE INVENTION It is a primary object of the present invention toprovide a new and improved construction of valveof the previouslymentioned'type which, without sacrificing the advantages of the knownconstructions, is simpler in construction and therefore considerablymore eco nomical to fabricate.

Now, in order to implement this object and others which will become morereadily apparent as the description proceeds, the invention contemplatesa shutoff or cutoff valve of the aforementioned type which is manifestedby the features that the sealing ring is clamped between a first pistonpart or portion and an annular spring cooperating with a second pistonpart or portion, the annular spring in the closed position of theplunger piston bearing against a stop which is fixed to the valvehousing, so that the annular spring is displaced relative to both of thepiston parts which are fixedly connected with one another during furthermovement of the actuation spindle in the closed direction in the senseof exerting anadditional axial compression upon the sealing ring.

An annular spring constitutes a very'spac e-saving resilient elementhaving extremely great structural mechanical effect because the stressesare almost uniformly divided over the cross-section of each annularspring element. The thus attained construction is therefore very simple,low in weight and accordingly economical. Since the annular spring ismoved by the housing stop in the sense of relaxing the spring, thespring elements moved relative to the piston during a subse 'quentopening operation remain in the last assumed position, whereby there isattained an equilibrium condition between the spring force of theannular spring and the reaction force occurring during compression ofthe sealing ring. In this manner, the sealing ring is always subjectedto a-certain elastic compression.

A particularly simple constructional manifestation of the invention canbe realized if the annular spring consists of a ring-member which at itsoutside surface is cylindrical, and also having an inner conical surfacewhich cooperates with a conical surface at the second piston part orportion, the cone of conical surfaces increasing in diameter in theclosing direction. The annu- 2 lar spring then'directly forms thesupport for the sealing ring and its diameter practically coincides withthe di- .mensions of the sealing-ring. Both of the piston portions, ifdesired with axial non-'displaceable mounting thereof at a spindle end,are advantageously connected with one another by a screw connection,wherein with the sealing ring inserted there is produced by means ofsaid screw connection, the stressing of the annular spring. I

During assembly there occurs the stressing of the annular spring andcompression of the sealing ring by such spring, so that the assembly ofthe sealing ring with the inventive shutoff valve isnotassociated withany more expenditures than for a conventional sleeve valve. The coneangle at the second piston part advantageously amounts to 7 to 20",preferably 9 to 16. The exact accommodation of the cone angle dependsupon theelastic properties of the sealing ring because the accommodationmust occur between the spring compression which decreases from theouterperiphery towards the inside, and which can be realized when the sealingring is assembled by carrying out a rotation or turning of the annularspring through a maximum of 5 during interconnection of both pistonparts. The sealing ring is therefore fixedly clampedespecially well. atthe outer circumference, wherein owing to the reduction of thecompressive force towards the valve or plunger piston axis and due tothe turning orrotation of the annular spring there is avoided everyforce component which would act in the sense of pressing the sealingring out of its clamped position. i

If the difference of the cone angle between the end surface of thesealing ring and the countersurface at the as well as' also duringtheoperation of the valve, the

edge of the annular spring which is present between the countersurfacefor the sealing ring and the countersurface for the piston cone isadvantageously rounded, be-

cause this edge is continuously in contact with the pis-- ton. A verysimple construction of piston can be obtained if the cone or conicalsurface at the second piston part transforms into a substantiallycylindrical receiving or mounting surface for the sealing ring. Theannular spring then can be mounted in the most simple manner, so thatthere is formed a receiving or mounting surface for the sealing ringwhich consists of a radial surface and cylindrical surface. If corrosionresistance is required for the annular spring construction, then thisannular spring can be advantageously fabricated from austenitic steelwhich has imparted to it the required strength by cold working. In orderto improve the sliding properties between the second piston part and theannular spring, it is recommended in a great many instances to alsocarry out surface treatment. At the piston, which oftentimes can consistof conventional carbon steel, it is recommended in such cases to carryout chromium plating, whereas the annular spring can be soft nitrided(Tenifer process).

BRIEF DESCRIPTION OF THE DRAWING DETAILED DESCRIPTION OF THE PREFERREEMBODIMENTS Describing now the drawings, the exemplary embodiment ofshutoff valve as depicted therein will be recognized to comprise ahousing 1 having an inlet opening, such as opening lb, and. an outletopening, such as opening la, as well as an opening 1c for thedisplacement compartment of the plunger piston 7. This opening 1c isclosed by an upper closure portion 2 with the aid of setscrews 3 or thelike and an intermediately disposed sealing member or gasket 4. At thisupper closure portion 2 a valve spindle 5 is appropriately mounted to beaxially displaceable through the agency of a threaded connection,generally indicated by reference character 30, so that by means of thehandwheel 6 the plunger piston 7 secured to the other end 5a of thespindle 5 can be axially displaced. Sealing of the spindle 5 isundertaken by means of a packing sleeve or bushing 8 for instance. Thespindle 5 possesses at its one end 5a a collar 5b which insures for theaxial non-displaceability of the piston 7 which consists of two pistonparts or portions 7' and 7 and which are fixed or clamped together bymeans of the screws 20 or the like.

The one upper piston part 7' is rotatably mounted upon the end 5a of thespindle 5 andpossesses an end face 10 of substantiallycylindrical shapefor supporting a sealing ring 1 1, whereas a second end face 12 servingfor clamping this sealing ring 1 1 is formed by a surface of an annularor ring-shaped spring 13 having an inner conical surface 13b and whichbears upon a cone or conical surface 14 of the second lower piston part7" and which conical surface increases in. diameter in the closeddirection of the piston. The dimensions of the pistons parts 7 and 7 thesealing ring 11, and the annular spring 13 are chosen such that duringsecuring or clamping together of both piston parts 7 and 7" by means ofthe screws until impact of both piston parts against one another atlocation 16, the annular spring 13 is stressed orclamped to such anextent that there is realized the required axial compression of suchsealing ring 11.

The annular spring 13 originally possesses the position and shape shownin phantom lines in FIG. 2, which upon clamping together of the pistonparts 7' and 7" and rotation or turning of the cross-section andenlargement of the diameter of the spring transforms into moves relativeto the lower the full-line position. The end surface 12 of the annularspring 13 which acts as a countersurface confronting the sealing ring 11is therefore originally inclined towards the vertical axis of thespindle 5 and possesses a conical configuration; during clampingtogether of the piston parts the annular spring 13 is downwardlydisplaced, whereby it increases in diameter and the end surface 12confronting the sealing ring 11, which originally was conical, conformsinto a planar or flat surface, as shown in full lines in FIG. 2. In sodoing, the

parts of the annular spring at the region of such end surface, and whichare located further towards the outside, move through a greater axialpath than the further inwardly disposed parts of the annular spring, sothat the further outwardly located parts exert a greater reaction forcein the direction of the original position upon the sealing ring 11. Dueto the additional twisting or rotation of the annular spring, there isrealized an additional compressive force at the regions of the outersubstantially cylindrical jacket or surface of the sealing ring 11 whichtherefore'is continuously subjected to an axial force which worksagainst an unlimited enlargement of the outer periphery of the sealingring.

As soon as through rotation of the handwheel 6 the piston 7 is broughtby thespindle 5 into its lower terminal position then the annular spring13 bears by means of its bevelled portion 13a at a shoulder 15 defininga fixed stop of the housing 1. As soon as then the spindle 5, throughthe agency of the handwheel 6, begins to move the piston 7 in the senseof a further closing movement, then the sealing ring 11. is furtheraxially compressed together, whereby the annular spring 13 piston part7" in the sense of relaxing the spring. During subsequent opening of thevalve, the annular spring 13 then remains practically in the displacedposition, but it still acts upon the sealing ring 1 1 with the remainingrestoring force in the sense of carrying out a resilient axialcompression. The sealing ring 11 is therefore continuously subjected tosuch compressive force or compression which in the closed position ofthe piston 7 can be increased due to further application of a spindleforce acting in the closing direction, so that the sealing ring 1 1bears in a faultless sealing manner against the housing bore 1d. Ifnecessary, this housing bore can be providedwith a lining formed ofcorrosion resistant steel to safeguard against corrosion effects.

Further, as already indicated above, the difference of the cone anglebetween the end surface 1 la of the sealing ring and the countersurface12 of the annular spring 13 and between the conical surface 14at-the'second piston part 7 and the countersurface 13b at the annularspring 13 are of the same magnitude and in a range between 0.5 and 4.Furthermore, a rounded edge, as generally indicated by referencecharacter 130, .is ad vantageously provided between the countersurface12 at the annular spring 13 for the sealing ring 11 and thecountersurface 13b for the conical surface 14 of the second piston part7 While there is shown and described present preferred embodiments ofthe invention, it is to be distinctlyunderstood that the invention isnot limited thereto, but may be otherwise variously embodied andpracticed within the scope of the following claims.

What is claimed is:

l. A shutoff valve comprising a valve housing, a plunger pistondisplaceably mounted within said hous- 'ing, at least one axiallycompressible sealing ring caropen position and a closed position, theaxial elasticcompressive force increasing in the closed position of theplunger piston during further movement of the actuation spindle carryingsaid plunger piston, said plunger piston having a first piston part anda second piston part, means for fixedly interconnecting said pistonparts with one another, an annular spring cooperating with said secondpiston part, said sealing ring being clamped between the first pistonpart and said annular spring cooperating with said second piston part, afixed stop stationarily mounted at the valve housing, said annularspring bearing against the fixed stop in the closed position of theplunger piston so that the annular spring is displaced relative to bothof the fixedly connected piston parts during further movement of theactuation spindle in the closed direction in the sense of exerting anadditional axial compression upon the sealing ring.

2. The shutoff valve as defined in claim 1', wherein the annular springcomprises a ring member having an external substantially cylindricalsurface, said ring member having an inner substantially conical surface,

said second piston part having a conical surface, the

cluding means for providing an axial non-displaceable' mounting of saidpiston at one end of the spindle.

5. The'shutoff valve as defined in claim 3, wherein the cone angle ofthe conical surface at the second piston part is in a range of 7 to 20.

6. The shutoff valve as defined in claim 5, wherein the cone angle is ina range of 9 to 16.

7. The shutoff valve as defined in claim 5, wherein said sealing ring issubjected to an additional axial compressive force which decreases fromthe outer circumference thereof towards the inside, said additionalaxial compressive force being produced with the inserted sealing ringthrough turning of the annular spring through a maximum of 5 duringinterconnection of both piston parts in that an originally conical endsurface of the annular spring confronting the sealing ring is deformedinto a substantially flat surface.

8. The shutoff valve as defined in claim 7, wherein the originallyconical end surface of the annular spring defines a counte'rsurface fora contronting' end surface of the sealing ring, and wherein said annularspring possesses a further countersurface confronting the conicalsurface at the second piston part, and wherein the difference of thecone angle between the end surface of the sealing ring and itsconfronting countersurface of the annular spring and between the conicalsurface of the secondpiston part and its confronting countersurface atthe annular spring are of the same magnitude and in a range between 0.5and 4.

9. The shutoff valve as defined in claim 8, wherein a rounded edge isprovided for the annular spring between its countersurface for thesealing ring and its countersurface for the conical surface of thesecond piston part.

10. The shutoff valve as defined in claim 9, wherein the conical surfaceat the second piston part transforms .into a substantially cylindricalreceiving surface for the sealing ring.

11. The shutoff valve as defined in claim 1, wherein the annular springconsists of cold worked austenitic steel.

12. The shutoff valve as defined in claim 2, wherein the conical surfaceat the second piston part is chromium plated and the annular spring isnitrided.

13. The shutoff valve as defined in claim 1', wherein the annular springpossesses at its outer circumference a bevelled portion for cooperationwith the fixed stop.

1. A shutoff valve comprising a valve housing, a plunger pistondisplaceably mounted within said housing, at least one axiallycompressible sealing ring carried by such plunger piston for exerting asealing action against the housing, said sealing ring being subjected toan axial elastic compressive force throughout each actuation positionthereof, an actuation spindle for carrying said plunger piston to movethe latter between an open position and a closed position, the axialelastic compressive force increasing in the closed position of theplunger piston during further movement of the actuation spindle carryingsaid plunger piston, said plunger piston having a first piston part anda second piston part, means for fixedly interconnecting said pistonparTs with one another, an annular spring cooperating with said secondpiston part, said sealing ring being clamped between the first pistonpart and said annular spring cooperating with said second piston part, afixed stop stationarily mounted at the valve housing, said annularspring bearing against the fixed stop in the closed position of theplunger piston so that the annular spring is displaced relative to bothof the fixedly connected piston parts during further movement of theactuation spindle in the closed direction in the sense of exerting anadditional axial compression upon the sealing ring.
 2. The shutoff valveas defined in claim 1, wherein the annular spring comprises a ringmember having an external substantially cylindrical surface, said ringmember having an inner substantially conical surface, said second pistonpart having a conical surface, the inner conical surface of the ringmember cooperating with the conical surface of the second piston part,said conical surface of the second piston part increasing in diameter inthe closed direction.
 3. The shutoff valve as defined in claim 2,wherein said means for connecting both piston parts with one anothercomprises means providing a screw connection, and wherein with thesealing ring inserted between said piston parts the screw connectionstresses the annular spring.
 4. The shutoff valve as defined in claim 3,further including means for providing an axial non-displaceable mountingof said piston at one end of the spindle.
 5. The shutoff valve asdefined in claim 3, wherein the cone angle of the conical surface at thesecond piston part is in a range of 7* to 20*.
 6. The shutoff valve asdefined in claim 5, wherein the cone angle is in a range of 9* to 16*.7. The shutoff valve as defined in claim 5, wherein said sealing ring issubjected to an additional axial compressive force which decreases fromthe outer circumference thereof towards the inside, said additionalaxial compressive force being produced with the inserted sealing ringthrough turning of the annular spring through a maximum of 5* duringinterconnection of both piston parts in that an originally conical endsurface of the annular spring confronting the sealing ring is deformedinto a substantially flat surface.
 8. The shutoff valve as defined inclaim 7, wherein the originally conical end surface of the annularspring defines a countersurface for a contronting end surface of thesealing ring, and wherein said annular spring possesses a furthercountersurface confronting the conical surface at the second pistonpart, and wherein the difference of the cone angle between the endsurface of the sealing ring and its confronting countersurface of theannular spring and between the conical surface of the second piston partand its confronting countersurface at the annular spring are of the samemagnitude and in a range between 0.5* and 4*.
 9. The shutoff valve asdefined in claim 8, wherein a rounded edge is provided for the annularspring between its countersurface for the sealing ring and itscountersurface for the conical surface of the second piston part. 10.The shutoff valve as defined in claim 9, wherein the conical surface atthe second piston part transforms into a substantially cylindricalreceiving surface for the sealing ring.
 11. The shutoff valve as definedin claim 1, wherein the annular spring consists of cold workedaustenitic steel.
 12. The shutoff valve as defined in claim 2, whereinthe conical surface at the second piston part is chromium plated and theannular spring is nitrided.
 13. The shutoff valve as defined in claim 1,wherein the annular spring possesses at its outer circumference abevelled portion for cooperation with the fixed stop.